Oops, i forgot to leave a comment with my review earlier...
i found the visual style stunning, it was very fun to experience and try to play! It was quite a difficult game, although i forgot jumping was a thing in my excitement lol. It was a bit loud at times but that's not too big of a problem! The game it self was fun to play and again wow, it was beautiful. Even more impressive you didn't use an engine, and this being your first jam, fantastic work.
(Also I just remembered, I'm not sure of this was user error, intentional design or a quirk in the game but i think i got stuck in the right side wall once. However take this with a grain of salt as I am unable to play again atm to test and i played couple hours ago)
Have you thought about adding mobile compability? It could be fun to play on the phone as well!